Marginal and Saline Soils: Characteristics, Rehabilitation, and Reclamation, Quizzes of Agricultural engineering

Download Marginal and Saline Soils: Characteristics, Rehabilitation, and Reclamation and more Quizzes Agricultural engineering in PDF only on Docsity! TERM 1 Marginal Soils DEFINITION 1 Unable to support plant growth without the appropriate long-term management scheme TERM 2 Marginal Soils characteristics DEFINITION 2 - has to be corrected for the area to be productive Infertile Low in organic matter Often acidic Subject to severe erosion and surface run-off TERM 3 Rehabilitating Marginal Soils DEFINITION 3 Control soil erosion - used fast-growing perennial vegetation (choice of first plant is key!) Enrich soil organic matter - increases fertility and improves soil physical properties Correct Soil pH Conservation tillage plant cash crops that cover the soil and employ crop rotation Apply fertilizers TERM 4 Acid-sulfate soils DEFINITION 4 Extremely acid (pH<3.5) due to large amounts of reduced forms of sulfur that are oxidized to sulfuric acid if soil is exposed to oxygen when they are drained or excavated May be corrosive TERM 5 Rehabilitation of acid-sulfate soils DEFINITION 5 Prevention is Key! Sulfide-bearing wetlands are better left undisturbed Re-Flooding (restoring the hydrology) of drained coastal wetlands. This will convert oxidized forms of sulfur into reduced forms. - Drained coastal -> re-flooding -> restored wetland (SO4^2-) -> anaerobic conditions-> (H2S) Excavated sulfide - Route the acid water to a treatment wetland Application of liming material (CaCO3) TERM 6 Sodium Adsorption Ratio (SAR) DEFINITION 6 Tells us how much sodium is absorbed compared to two of the most common cations in the soil Higher SAR means that the scorpion sites are dominated by sodium Soils or soil solutions that have high electrical conductivity has a high salt concentration TERM 7 Sanitization DEFINITION 7 Accumulation of soluble salts Mainly chloride and sulfates of calcium, magnesium, potassium and sodium TERM 8 Salinity DEFINITION 8 Electrical conductivity (EC) of a saturated soil extract TERM 9 Sodicity DEFINITION 9 Refers to the concentration of sodium TERM 10 Saline Soils DEFINITION 10 Containing sufficient soluble salts to adversely affect the growth of most plants Electrical conductivity of saturated extract is >4 dS m^-1 (at 25 C) SAR is <13 and pH is <8.5 A non-sodic soil